(Bloomberg) -- The head of Venezuela’s National Assembly Juan Guaido was detained by intelligence police SEBIN on Sunday, according to a message posted on Guaido’s Twitter account.

The whereabouts of the 35-year-old opposition leader are unknown, the message said. Guaido’s vehicle was intercepted at a highway, according to a video supposedly showing his detention that was disseminated by members of his party and other opposition leaders on Twitter. Guaido was released after a few minutes, according to an EFE report quoting sources close to the head of the National Assembly.

Two journalists, Osmary Hernandez from CNN Espanol and Beatriz Adrian from Noticias Caracol, were also taken by intelligence police in Venezuela square in Caracas on Sunday, opposition leaders said on Twitter.

Guaido spoke in front of about 1,000 people on Friday in eastern Caracas as part of a protest against President Nicolas Maduro’s swearing-in ceremony. People in the crowd chanted “Guaido for President!” as the leader of the only remaining opposition-controlled authority in Venezuela said he was prepared to assume the presidency.

It was the first major political protest since hundreds of thousands of Venezuelans took to the streets in 2017 over hyperinflation, rampant shortages and a soaring crime rate. Organized demonstrations fizzled over the past year as Maduro consolidated power and cracked down on dissent. Demonstrations now largely consist of small, spontaneous gatherings over faltering public services and food programs.

Guaido has called for a nationwide protest Jan. 23, the date in January 1958 when opposition parties and soldiers overthrew military dictator Marcos Perez Jimenez.

(Adds further reports of detentions.)

To contact the reporter on this story: Laura Millan Lombrana in Santiago at lmillan4@bloomberg.net

To contact the editors responsible for this story: Luzi Ann Javier at ljavier@bloomberg.net, James Ludden

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